Potassium phosphate
[CAS# 7778-53-2]

Identification

• Classification: Inorganic chemical industry >> Inorganic salt >> Phosphides, metal phosphoric acid, metaphosphoric acid, hypophosphorous acid and pyrophosphate
• Name: Potassium phosphate
• Synonyms: Tripotassium phosphate; Tripotassium orthophosphate
• Molecular Formula: K₃PO₄
• Molecular Weight: 212.26
• CAS Registry Number: 7778-53-2
• EC Number: 231-907-1
• SMILES: [O-]P(=O)([O-])[O-].[K+].[K+].[K+]

Properties

• Density: 2.564
• Melting point: 1340 °C
• Water solubility: 50.8 g/100 mL (25 °C)

Safety Data

• Hazard Symbols: GHS05;GHS07 Danger
• Risk Statements: H315-H318-H319-H335
• Safety Statements: P261-P264-P264+P265-P271-P280-P302+P352-P304+P340-P305+P351+P338-P305+P354+P338-P317-P319-P321-P332+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Specific target organ toxicity - single exposure	STOT SE	3	H335
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319
Serious eye damage	Eye Dam.	1	H318
Skin corrosion	Skin Corr.	1A	H314
Substances or mixtures corrosive to metals	Met. Corr.	1	H290
Skin corrosion	Skin Corr.	1B	H314
Eye irritation	Eye Irrit.	2A	H319
Acute toxicity	Acute Tox.	4	H302

Discovery and Applications

Potassium phosphate refers to a group of salts containing potassium (K?) and phosphate (PO4³?) ions and includes several compounds, each with different properties and applications: Monopotassium phosphate (KH2PO4), also known as potassium dihydrogen phosphate, is commonly used in fertilizers and as a buffer in foods and pharmaceuticals. Dipotassium phosphate (K2HPO4), is used as a buffer in fertilizers, food additives, and industrial processes. Tripotassium phosphate (K3PO4), is primarily used in cleaning and detergent formulations due to its alkalinity and chelating properties. These compounds are soluble in water and can be easily broken down into potassium and phosphate ions, making them useful in a wide range of applications.

Potassium phosphate salts are widely used as buffers in pharmaceuticals, foods, and cosmetics. They help keep the pH level in formulations stable, ensuring product efficacy and long-term stability. Monopotassium phosphate is particularly valued for its ability to adjust pH in a controlled manner. Dipotassium phosphate and monopotassium phosphate are important components of water-soluble fertilizers. They provide plants with readily available potassium and phosphate nutrients that promote healthy growth, improve root development, and increase crop yields. These salts are particularly beneficial in hydroponics and greenhouse agriculture.

Potassium phosphate salts are used as food additives to regulate the acidity of processed foods and improve their texture. They function as emulsifiers, stabilizers, and leavening agents in baked goods, dairy products, and beverages. These compounds help maintain product consistency and extend shelf life. In brewing, dipotassium phosphate is added to beer during fermentation to adjust pH and increase yeast activity. It helps ensure fermentation consistency and enhances the flavor profile of the final product.

Monopotassium phosphate and dipotassium phosphate are used as active ingredients and excipients in pharmaceutical formulations. They are used as buffers in oral medications and injectable solutions to ensure optimal pH for drug stability and bioavailability. Potassium phosphate salts are used in intravenous fluids to replenish potassium and phosphate electrolytes for patients with electrolyte imbalances or deficiencies. These solutions help maintain proper fluid balance and support cellular function.

References

1986. Simplified enzymatic synthesis and biodistribution of 11C-S-adenosyl-l-methionine. European Journal of Nuclear Medicine and Molecular Imaging, 12(1).
DOI: 10.1007/bf00261008

1979. De novo fatty acid synthesis and fatty acid elongation catalyzed by subcellular fractions from hog and human aorta. Lipids, 14(5).
DOI: 10.1007/bf02533461

1979. Tissue and regional distribution of cysteic acid decarboxylase. A new assay method. Neurochemical Research, 4(4).
DOI: 10.1007/bf00964144